Author

Tan, Jia Hui.

Date of Issue

2009

School

School of Materials Science and Engineering

Related Organization

Institute of Chemical and Engineering Sciences

Abstract

The purpose of this study is to investigate the change in chemical structures of
biopolymers PLGA 80:20 and PLLA during thermal and oxidative degradation
by the means of in-situ Raman spectroscopy monitoring. Both isothermal and
non-isothermal testing, with or with little presence of oxygen, will be conducted
to monitor the changes in chemical configuration of biopolymers with respect to
the increasing degradation temperature or time. It was found that the number of
carbonyl groups and vas CH3 and vCH stretching regions decreased with
increasing degradation. The former was due to degradation of carbonyl group
while the latter was due to random chain scission. The COC regions (1092
v/cm-1, 1179 v/cm-1 and 1216 v/cm-1) were very stable throughout the whole
degradation process. Interestingly, the CCO region (398 v/cm-1 to 441 v/cm-1)
increased with prolonged degradation time. This was due to the increase in
degree of crystallinilty (DOC) of the biopolymers. This increase could be further
confirmed by the analysis done by TGA.